In the prior art, systems are already known which enable at least two electro-dynamic machines to operate in a synchronised manner. In particular, when the electro-dynamic machine is a motor, the synchronisation operates so that at least two motors work at the same time or with the same electro-mechanical characteristics, e.g. position, speed, power, or motor torque. In order to achieve this objective, efforts have been made to construct an auto-synchronising means (i.e. a means for obtaining automatic synchronisation) associated with each motor, such that a multi-motor mechanical system can be more easily and more effectively synchronised in its operation.
A particularly relevant application of such a system is that of vehicle screen wiping apparatus, e.g. for windshield wipers, in which most typically two wipers are driven in synchronised movement when a single motor is used. In current practice, it is necessary to drive the pivot axes of the two wipers by means of a linkage which is bulky, noisy, and costly both in price and in energy.